Non-aqueous secondary batteries (hereinafter, also referred to simply as “secondary batteries”), such as lithium ion secondary batteries, have characteristics such as compact size, light weight, high energy density, and the ability to be repeatedly charged and discharged, and are used in a wide variety of applications. A secondary battery generally includes battery members such as electrodes (positive electrode and negative electrode) and a separator that isolates the positive electrode and the negative electrode from one another and prevents short-circuiting between the positive and negative electrodes.
A binder that displays binding capacity may be used with an objective of, for example, binding components in a battery member such as those described above or binding battery members to one another. For example, in recent years, battery components including functional layers, such as a porous membrane layer for improving heat resistance and strength or an adhesive layer for improving adhesion between battery members, have been used in secondary batteries, and studies have been undertaken in relation to improving, as a binder used in such functional layers, a binder for a non-aqueous secondary battery that contains a particulate polymer dispersed in an aqueous medium (for example, refer to PTL 1 and 2).